Curable unsaturated resin composition

ABSTRACT

The present invention provides a curable unsaturated resin composition, which has less odor characteristics and high safety and is also superior in thin film coating characteristics in a coating film. The curable unsaturated resin composition contains a polymerizable unsaturated resin (A) having two or more polymerizable unsaturated double bonds in a molecule, a hydroxyalkyl (meth)acrylate (B), and an unsaturated compound (C) having one or more cyclohexene rings and two or more allyl ether groups in a molecule, which is liquid at normal temperature.

TECHNICAL FIELD

[0001] The present invention relates to a curable unsaturated resincomposition, which has less odor characteristics and is also superior insafety and drying characteristics in a thin film portion of a coatingfilm.

BACKGROUND ART

[0002] Unsaturated polyester resins have hitherto been used as coatingcompositions for woodworking, molded articles, sealing materials andadhesives because they have good gloss and desirable thick appearance,and also impart beautiful finishing appearance. Also the unsaturatedpolyester resin is used in combination with a styrene monomer, as acrosslinkable unsaturated monomer, in view of the curability andphysical properties. However, in view of environmental problems, asocial trend of regulating the use of the styrene monomer, that cancause problems such volatility, odor, and toxicity, has recentlyincreased. When using the styrene monomer as coating materials such ascoating compositions, there arise problems in that grain depression of acoating film is caused by volatilization of the styrene monomer duringcuring of the coating film, resulting in variability in quality.

[0003] To cope with these problems, (1) a method of reducing the contentof a styrene monomer by decreasing the molecular weight of anunsaturated polyester resin, (2) a method of suppressing volatilizationof a styrene monomer by adding wax to a unsaturated polyester resincomposition containing a crosslinkable unsaturated monomer, and (3) amethod of using a crosslinkable unsaturated monomer having lowvolatility in place of a styrene monomer are proposed. However, themethods (1) and (2) do not constitute a radical solution to the aboveproblems because of the use of the styrene monomer, while those havingsatisfactory curability and drying characteristics, especially thin filmdrying characteristics in the coating film, have not been obtained bythe method (3).

DISCLOSURE OF INVENTION

[0004] An object of the present invention is to provide a curableunsaturated resin composition, which has less odor characteristics andhigh safety and is also superior in thin film drying characteristics ina coating film.

[0005] The present inventors have intensively researched about thisobject, and thus the present invention has been completed.

[0006] The present invention provides a curable unsaturated resincomposition comprising a polymerizable unsaturated resin (A) having twoor more polymerizable unsaturated double bonds in a molecule, ahydroxyalkyl (meth)acrylate (B), and an unsaturated compound (C) havingone or more cyclohexene rings and two or more allyl ether groups in amolecule, which is liquid at normal temperature.

BEST MODE FOR CARRYING OUT THE INVENTION

[0007] The present invention will now be described in detail.

[0008] Examples of the polymerizable unsaturated resin (A) having two ormore polymerizable unsaturated double bonds in a molecule of the presentinvention include unsaturated polyester resin, epoxy (meth)acrylate,urethane (meth)acrylate, and polyester (meth)acrylate, and thenumber-average molecular weight is more than 1000, and preferably withina range from 1000 to 5000. These polymerizable unsaturated resins may beused alone and, if necessary, two or more kinds thereof may be used incombination. Among these polymerizable unsaturated resins, anunsaturated polyester resin is particularly preferred in view of thecurability, drying characteristics, and coating film physicalproperties.

[0009] The unsaturated polyester resin used in the present invention isobtained from dibasic acids containing α,β-unsaturated dibasic acid andpolyhydric alcohols. Among these unsaturated polyester resins, anair-drying characteristics-imparting unsaturated polyester resin isparticularly preferred in view of the drying characteristics in thecoating film.

[0010] Examples of the air-drying characteristics-imparting unsaturatedpolyester resin include those using a compound containing a cyclicaliphatic unsaturated polybasic acid and a derivative thereof as adibasic acid component, those using a hydroxy compound having an allylether group as a polyhydric alcohol component, those using adicyclopentadiene-based compound, and those using linseed oil and tungoil as a drying oil. Among these air-drying characteristics-impartingunsaturated polyester resins, those using a compound containing a cyclicaliphatic unsaturated polybasic acid and a derivative thereof as adibasic acid component are particularly preferred in view of the dryingcharacteristics in the coating film.

[0011] Examples of the cyclic aliphatic unsaturated polybasic acid andthe derivative thereof include tetrahydrophthalic anhydride,methyltetrahydrophthalic anhydride, endomethylenetetrahydrophthalicanhydride, α-terpinene maleic anhydride adduct, and trans-piperylenemaleic anhydride adduct. Among these compounds, methyltetrahydrophthalicanhydride is particularly preferred.

[0012] As the hydroxy compound having an allyl ether group, publiclyknown and conventional compounds can be used, and typical examplesthereof include allyl ether compounds of polyhydric alcohols, such asethylene glycol monoallyl ether, diethylene glycol monoallyl ether,triethylene glycol monoallyl ether, polyethylene glycol monoallyl ether,propylene glycol monoallyl ether, dipropylene glycol monoallyl ether,tripropylene glycol monoallyl ether, polypropylene glycol monoallylether, 1,2-butylene glycol monoallyl ether, 1,3-butylene glycolmonoallyl ether, hexylene glycol monoallyl ether, octylene glycolmonoallyl ether, trimethylolpropane diallyl ether, glycerin diallylether, and pentaerythritol triallyl ether.

[0013] Examples of the α,β-unsaturated dibasic acid as the dibasic acidcomponent used to prepare the unsaturated polyester resin include maleicacid, maleic anhydride, fumaric acid, itaconic acid, and itaconicanhydride. Examples of the saturated dibasic acid as the dibasic acidcomponent include phthalic acid, phthalic anhydride, halogenatedphthalic anhydride, isophthalic acid, terephthalic acid,hexahydrophthalic acid, hexahydrophthalic anhydride,hexahydroterephthalic acid, hexahydroisophthalic acid, succinic acid,malonic acid, glutaric acid, adipic acid, sebacic acid, 1,12-dodecanoicdiacid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylicacid, 2,3-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylicanhydride, 4,4′-biphenyldicarboxylic acid, and dialkyl esters thereof.Examples of polyhydric alcohols include ethylene glycol, diethyleneglycol, triethylene glycol, polyethylene glycol, propylene glycol,dipropylene glycol, polypropylene glycol, 2-methyl-1,3-propanediol,1,3-butanediol, neopentyl glycol, hydrogenated bisphenol A,1,4-butanediol, adduct of bisphenol A and propylene oxide or ethyleneoxide, 1,2,3,4-tetrahydroxybutane, glycerin, trimethylolpropane,1,3-propanediol, 1,2-cyclohexane glycol, 1,3-cyclohexane glycol,1,4-cyclohexane glycol, 1,4-cyclohexanedimethanol, paraxylene glycol,bicyclohexyl-4,4′-diol, 2,6-decalin glycol, and 2,7-decalin glycol.

[0014] The epoxy (meth)acrylate preferably has two or more(meth)acryloyl groups in a molecule, and is obtained by reacting anepoxy resin and a (meth)acrylic acid in the presence of anesterification catalyst.

[0015] Examples of the epoxy resin include bisphenol type and novolaktype epoxy resins, and a mixture of bisphenol type and novolak typeepoxy resins, and the average epoxy equivalent thereof is preferablywithin a range from 150 to 450.

[0016] The bisphenol type epoxy resin is a glycidyl ether type epoxyresin having substantially two or more epoxy groups in a moleculeobtained by reacting epichlorohydrin and bisphenol A or bisphenol F, amethyl glycidyl ether type epoxy resin obtained by reacting methylepichlorohydrin and bisphenol A or bisphenol F, or an epoxy resinobtained from an alkylene oxide adduct of bisphenol A andepichlorohydrin or methyl epichlorohydrin. Typical examples of thenovolak type epoxy resin include epoxy resin obtained by reacting phenolnovolak or cresol novolak with epichlorohydrin or methylepichlorohydrin.

[0017] In the preparation of the epoxy (meth)acrylate, acrylic acid andmethacrylic acid are used, but another unsaturated monobasic acid, forexample, cinnamic acid, crotonic acid, maleic acid monomethyl,monopropyl maleate, mono(2-ethylhexyl)maleate, or sorbic acid can beused in combination. The reaction between the epoxy resin and the(meth)acrylic acid is preferably conducted at a temperature within arange from 60 to 140° C., and particularly preferably from 80 to 120°C., using an esterification catalyst.

[0018] As the esterification catalyst, for example, a tertiary aminesuch as triethylamine, N,N-dimethylbenzylamine, N,N-dimethylaniline, ordiazabicyclooctane, or a publicly known catalyst such astriphenylphosphine or diethylamine hydrochloride can be used as it is.

[0019] The urethane (meth)acrylate is preferably obtained by reactingpolyol, polyisocyanate and a (meth)acrylate having one or more hydroxylgroups in a molecule, and has two or more (meth)acryloyl groups in amolecule.

[0020] The polyol preferably has a number-average molecular weight of200 to 3000, and particularly preferably 400 to 2000. Typical examplesof the polyol include polyether polyol, polyester polyol, polycarbonatepolyol, and polybutadiene polyol.

[0021] The polyether polyol can also include polyol obtained by addingthe alkylene oxide to bisphenol A and bisphenol F, in addition to apolyalkylene oxide such as polyethylene glycol, polypropylene glycol, orpolytetramethylene glycol.

[0022] The polyester polyol is a condensed polymer of saturated dibasicacids and polyhydric alcohols, or a ring-opening polymer of a cyclicester compound such as polycaprolactone. Examples of dibasic acids usedherein include phthalic acid, phthalic anhydride, halogenated phthalicanhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic acid,tetrahydrophthalic anhydride, hexahydrophthalic acid, hexahydrophthalicanhydride, hexahydroterephthalic acid, hexahydroisophthalic acid,succinic acid, malonic acid, glutaric acid, adipic acid, sebacic acid,1,12-dodecanedicarboxylic acid, 2,6-naphthalenedicarboxylic acid,2,7-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid,2,3-naphthalenedicarboxylic anhydride, 4,4′-biphenyldicarboxylic acid,and dialkyl esters thereof.

[0023] Examples of polyhydric alcohols include ethylene glycol,diethylene glycol, triethylene glycol, polyethylene glycol, propyleneglycol, dipropylene glycol, tripropylene glycol, polypropylene glycol,2-methyl-1,3-propanediol, 1,3-butanediol, neopentyl glycol, hydrogenatedbisphenol A, 1,4-butanediol, 1,6-hexanediol, adduct of bisphenol A andpropylene oxide or ethylene oxide, 1,2,3,4-tetrahydroxybutane, glycerin,trimethylolpropane, 1,3-propanediol, 1,2-cyclohexane glycol,1,3-cyclohexane glycol, 1,4-cyclohexane glycol,1,4-cyclohexanedimethanol, paraxylene glycol, bicyclohexyl-4,4′-diol,2,6-decalin glycol, and 2,7-decalin glycol.

[0024] Examples of the polyisocyanate include 2,4-tolylene diisocyanateand isomers thereof or a mixture of isomers (herein abbreviated to TDI),diphenylmethane diisocyanate, hexamethylene diisocyanate, isophoronediisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate,dicyclohexylmethane diisocyanate, tolidine diisocyanate, naphthalenediisocyanate, and triphenylmethane triisocyanate. These polyisocyanatescan be used alone, or two or more kinds of them can be used incombination. Among these polyisocyanates, diisocyanate, particularlyTDI, is preferably used.

[0025] Examples of the (meth)acrylate having one or more hydroxyl groupsin a molecule used in urethane (meth)acrylate includemono(meth)acrylates such as 2-hydroxyethyl (meth)acrylate,2-hydroxypropyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate,polyethylene glycol mono(meth)acrylate, and polypropylene glycolmono(meth)acrylate; and polyhydric (meth)acrylates such astris(hydroxyethyl)isocyanuric acid di(meth)acrylate, and pentaerythritoltri(meth)acrylate.

[0026] Examples of the method for preparing the urethane (meth)acrylateinclude (i) a method of preferably reacting polyisocyanate with polyolat a ratio of NCO/OH (=1.3 to 2) to form a terminal isocyanate compoundand reacting the terminal isocyanate compound with a hydroxylgroup-containing (meth)acrylate compound so that the amount ofisocyanate groups is almost the same as that of hydroxyl groups and (ii)a method of reacting a polyisocyanate compound with a hydroxylgroup-containing (meth)acrylate compound at a ratio of NCO/OH (=2 ormore) to form an isocyanate terminated compound and reacting thecompound with a polyol.

[0027] The polyester (meth)acrylate is a saturated or unsaturatedpolyester resin having two or more (meth)acryloyl groups in a molecule,and is obtained by reacting a terminal of a saturated or unsaturatedpolyester with a (meth)acrylic compound. The number-average molecularweight of such a resin is preferably within a range from 500 to 5000.

[0028] The saturated polyester is obtained by the condensation reactionbetween saturated dibasic acids and polyhydric alcohols, while theunsaturated polyester is obtained by the condensation reaction betweendibasic acids containing α,β-unsaturated dibasic acid and polyhydricalcohols, and has functional groups for introducing the (meth)acryliccompound into the terminal.

[0029] Examples of saturated dibasic acids include saturated dibasicacids described above, and unsaturated dibasic acids described above canbe used. Polyhydric alcohols can be used in polyester polyols describedabove.

[0030] Examples of the (met)acrylic compound used in the polyester(meth)acrylate include glycidyl esters of acrylic acid or methacrylicacid. Preferably, glycidyl (meth)acrylate is used.

[0031] As the hydroxyalkyl (meth)acrylate (B) used in the presentinvention, hydroxyalkyl (meth)acrylate, which has an alkyl group having1 to 4 carbon atoms, is preferred and hydroxyethyl methacrylate isparticularly preferred in view of the odor, safety, viscosity andcurability. As long as the effects of the present invention are notimpaired, a monomer having (meth)acryloyl groups can be used incombination. As the monomer, there can be used lauryl (meth)acrylate,cyclohexyl (meth)acrylate, benzyl (meth)acrylate, stearyl(meth)acrylate, tridecyl (meth)acrylate, dicyclopentenyloxyethyl(meth)acrylate, ethylene glycol monomethyl ether (meth)acrylate,ethylene glycol monoethyl ether (meth)acrylate, ethylene glycolmonobutyl ether (meth)acrylate, ethylene glycol monohexyl ether(meth)acrylate, ethylene glycol mono-2-ethylhexyl ether (meth)acrylate,diethylene glycol monomethyl ether (meth)acrylate, diethylene glycolmonoethyl ether (meth)acrylate, diethylene glycol monobutyl ether(meth)acrylate, diethylene glycol monohexyl ether (meth)acrylate,diethylene glycol mono-2-ethylhexyl ether (meth)acrylate, ethyleneglycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethyleneglycol di(meth)acrylate, dipropylene glycol di(meth)acrylate,tripropylene glycol (meth)acrylate, phenoxyethyl (meth)acrylate,di(meth)acrylate of polytetramethylene glycol, 1,3-butylene glycoldi(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycoldi(meth)acrylate, 2-hydroxy-1,3-dimethacryloxypropane,2,2-bis[4-(methacryloxyethoxy)phenyl]propane,2,2-bis[4-(methacryloxydiethoxy)phenyl]propane,2,2-bis[4-(methacryloxypolyethoxy)phenyl]propane, tetraethyleneglycoldiacrylate, ethylene oxide-modified (n=2) diacrylate of bisphenolA, ethylene oxide isocyanurate-modified (n=3) diacrylate, andpentaerythritol diacrylate monostearate in combination. In the case inwhich the wear resistance, scratch resistance, agitation resistance andchemical resistance of the resin and the surface of the cured articlemust be improved, a polyfunctional unsaturated monomer, and preferablytri- or polyfunctional (meth)acrylate ester monomer are used incombination. Specifically, polymerizable monomers such astrimethylolpropane tri(meth)acrylate, tetramethylolmethane triacrylate,tetramethylolmethane tetraacrylate, pentaerythritoltriacrylate,trimethylolpropanepropylene oxide-modified (n=1) triacrylate, ethyleneoxide isocyanurate-modified (n=3) triacrylate, ethylene oxideisocyanurate (n=3) ε-caprolactone-modified triacrylate,dipentaerythritol pentacrylate and dipentaerythritol hexaacrylate, andpentaerythritol tetra(meth)acrylate can be used in combination.

[0032] The unsaturated compound (C) having one or more cyclohexene ringsand two or more allyl ether groups in a molecule, which is liquid atnormal temperature, used in the present invention is preferably anunsaturated ester compound derived from an acid component (C1) made of acarboxylic acid having a cyclohexene ring and a hydroxy compound (C2)having two or more allyl ether groups in a molecule. It is obtained bythe esterification reaction at the reaction ratio so that the number ofhydroxyl groups is from 0.5 to 1.3 per carboxyl group. In order that theunsaturated compound (C) of the present invention be liquid at normaltemperature, the number-average molecular weight is preferably 1000 orless, and more preferably 700 or less. The viscosity of the unsaturatedcompound (C) of the present invention is preferably within a range from10 to 100 dPa·s/(25° C., B type viscometer), and more preferably from 15to 50 dPa·s/(25° C., B type viscometer).

[0033] The carboxylic acid (C1) having a cyclohexene ring iscyclohexenedicarboxylic acid, which may have an alkyl substituent and,for example, an anhydride of 4-cyclohexene-1,2-dicarboxylic acid(tetrahydrophthalic anhydride) and an anhydride3-methyl-4-cyclohexene-1,2-dicarboxylic acid (methyltetrahydrophthalicanhydride) are particularly preferred. The saturated dibasic acid may beused in combination, in addition to the carboxylic acid having acyclohexene ring.

[0034] The hydroxy compound (C2) having two or more allyl ether groupsin a molecule is a polyallyl ether of a polyhydric alcohol and, forexample, hydroxy compounds having a hydroxyl group and 2 to 4 allylether groups, such as trimethylolpropane diallyl ether, glycerin diallylether and pentaerythritol triallyl ether are particularly preferred. Inaddition to the hydroxy compounds, polyhydric alcohols may be used incombination.

[0035] The mixing ratio of the polymerizable unsaturated resin (A), thehydroxyalkyl methacrylate (B) and the unsaturated compound (C),(A):(B):(C), is preferably within a range from 25-85% by weight:10-55%by weight:5-20% by weight, and more preferably from 40-70% byweight:20-40% by weight:10-20% by weight. When the mixing ratio is sucha weight ratio, the resulting curable unsaturated resin composition hasa proper viscosity and a good handlability, and is also superior incurability and drying characteristics.

[0036] The curable unsaturated resin composition of the presentinvention can be cured at normal temperature or by heating. To thecomposition, polymerization initiators are usually added and, ifnecessary, polymerization accelerators are added.

[0037] Examples of the polymerization initiator include organicperoxide. Specifically, publicly known polymerization initiators such asdiacyl peroxide, peroxy ester, hydroperoxide, dialkyl peroxide, ketoneperoxide, peroxy ketal, alkyl perester and percarbonate compounds can beused. The amount of the polymerization initiators is preferably within arange from 0.1 to 6 parts by weight based on 100 parts by weight of thetotal amount of the curable unsaturated resin composition.

[0038] Examples of the polymerization accelerator include metal soapssuch as cobalt naphthenate, cobalt octylate, zinc octylate, vanadiumoctylate, copper naphthenate, and barium naphthenate; metal cheletessuch as vanadium acetylacetate, cobalt acetylacetate, and ironacetylacetonate; N,N-substituted anilines such as, N,N-dimethylaniline,N,N-diethylaniline, p-toluidine, N,N-dimethyl-p-toluidine,N,N-bis(2-hydroxyethyl)-p-toluidine, 4-(N,N-dimethylamino)benzaldehyde,4-[N,N-bis(2-hydroxyethyl)amino]benzaldehyde,4-(N-methyl-N-hydroxyethylamino)benzaldehyde,N,N-bis(2-hydroxypropyl)-p-toluidine, N-ethyl-m-toluidine,triethanolamine, m-toluidine, diethylenetriamine, pyridine,phenylmorpholine, piperidine, and N,N-bis(hydroxyethyl)aniline;N,N-substituted-p-toluidines such as diethanolamine; and amines such as4-(N,N-substituted amino)benzaldehyde. In the present invention,amine-based and metal soap-based accelerators are preferred. The amountof the polymerization accelerator is preferably within a range from 0.1to 5 parts by weight based on the 100 parts by weight of the totalamount of the curable unsaturated resin composition. Two or more kindsof these polymerization accelerators may be used. Furthermore, thesepolymerization accelerators may be previously added to the unsaturatedresin composition, or may be added before use.

[0039] To maintain the storage stability, polymerization inhibitors canalso be added to the curable unsaturated resin composition of thepresent invention.

[0040] Examples of the polymerization inhibitor include trihydrobenzene,toluhydroquinone, 14-naphthoquinone, parabenzoquinone, hydroquinone,benzoquinone, hydroquinone monomethyl ether, p-tert-butyl catechol and2,6-di-tert-butyl-4-methylphenol. Preferably, 10 to 1000 ppm of thepolymerization inhibitor can be added to the unsaturated resincomposition.

[0041] The curable unsaturated resin composition of the presentinvention can also be cured by active energy rays. In that case,photopolymerization initiators are added to the composition. Thephotopolymerization initiator is not specifically limited as long as itgenerates radicals by an action of light, and examples thereof include4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone,diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one,1-(4-isopropylenephenyl)-2-hydroxy-2-methylpropan-1-one,1-(4-dodecylphenyl)-2-hydroxy-2-methylpropan-1-one,4-(2-hydroxyethoxy)-phenyl(2-hydroxy-2-propyl)ketone,1-hydroxycyclohexyl phenyl ketone,2-methyl1-[4-(methylthio)phenyl]-2-molpholinopropane-1, benzoin,benzoinmethyl ether, benzoinethyl ether, benzoinisopropyl ether, benzoinisobutyl ether, benzyl dimethyl ketal, benzophenone, benzoylbenzoicacid, methyl benzoyl benzoate, 4-phenylbenzophenone,hydroxybenzophenone, 4-benzoyl-4′-methyldiphenyl sulfide,3,3′-dimethyl-4-methoxybenzophenone, thioxanthone, 2-chlorothioxanthone,2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone,camphorquinone, dibenzosuberone, 2-ethylanthraquinone,4′,4′-diethylisophthalophenone,3,3′,4,4′-tetra(t-butylperoxycarbonyl)benzophenone, α-acyloxime ester,acyl phosphine oxide, methylphenyl glyoxylate, benzyl,9,10-phenanthrenequinone, and4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone. Examples of theauxiliary thereof include triethanolamine, triisopropanolamine,4,4′-dimethylaminobenzophenone (Michler's ketone),4,4′-diethylaminobenzophenone, 2-dimethylaminoethylbenzoic acid, ethyl4-dimethylaminobenzoate, (n-butoxy)ethyl 4-dimethylaminobenzoate,isoamyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate,2,4-diethylthioxanthone, and 2,4-diisopropylthioxanthone. Among thesecompounds, benzyl dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone,benzoyl isopropyl ether,4-(2-hydroxyethoxy)-phenyl(2-hydroxy-2-propyl)ketone,2-hydroxy-2-methyl-1-phenylpropan-1-one are preferably used.

[0042] In the curable unsaturated resin composition of the presentinvention, various additives such as fillers, ultraviolet absorbers,pigments, low-shrinking agents, antioxindats, plasticizers, aggregates,flame retardants, stabilizers, reinforcers may be used.

[0043] Examples of the filler include calcium carbonate, magnesiumcarbonate, barium sulfate, mica, talc, kaolin, clay, celite, asbestos,perlite, baryta, silica, silica sand, dolomite, limestone, plaster, finealuminum powders, hollow balloons, alumina, glass powder, aluminumhydroxide, white marble, zirconium oxide, antimony trioxide, titaniumoxide, molybdenum dioxide, and zinc stearate. These fillers are selectedtaking account of the handlability and the strength, appearance andeconomy of the resulting molded articles. Usually, calcium carbonate,aluminum hydroxide, silica and talc are often used. Fillers includesurface-treated fillers.

[0044] Examples of the pigment include inorganic pigments such astitanium white and carbon black and organic pigments such asphthalocyanine blue and quinacridone red. According to the color hue,various colorants can be used.

[0045] Examples of the reinforcer include glass fibers; organic fibersmade of vinylon, polyester and phenol; asbestos; and carbon fibers.

[0046] Examples of other additives include viscosity modifiers such asviscosity reducing agent, thixotropic agents, thixotropic auxiliaries,defoamers, leveling agents, silane coupling agents, and air blockingagents such as paraffin, and commercially available products can beused.

[0047] Solvents as the viscosity modifier are sometimes added to thecurable unsaturated resin composition of the present invention. Examplesof the solvent include toluene, xylene, methanol, ethanol, propanol,butanol, ethyl acetate, butyl acetate, acetone, and methyl ethyl ketone.

[0048] The curable unsaturated resin composition of the presentinvention is useful as coating materials, FRP molded articles, resinconcretes, patties, and cast products. It is particularly useful ascoating materials and coating compositions for woodworking.

EXAMPLES

[0049] The present invention will be described in more detail by way ofExamples, but the present invention is not limited to the followingExamples. In the specification, parts are by weight unless otherwisespecified.

Reference Example 1 Preparation of Air-Drying Characteristics-ImpartingUnsaturated Polyester Resin (A)

[0050] In a 2 L glass flask equipped with a nitrogen gas introducingtube, a reflux condenser and a stirrer, 502 g (4.74 mol) of diethyleneglycol, 320 g (2.75 mol) of fumaric acid and 305 g (1.83 mol) ofmethyltetrahydrophthalic anhydride are charged and heating is startedunder a nitrogen gas flow. The dehydration condensation reaction isconducted at an internal temperature of 200° C. using a conventionalmethod. After the acid value reached 29 KOH mg/g, 0.33 g oftoluhydroquinone is added. After cooling to 150° C., an air-dryingcharacteristics-imparting unsaturated polyester resin (UP-1), which issolid at normal temperature, was obtained.

Reference Example 2 Preparation of Air-Drying Characteristics-ImpartingUnsaturated Polyester Resin (A)

[0051] In a 2 L glass flask equipped with a nitrogen gas introducingtube, a reflux condenser and a stirrer, 509 g (4.80 mol) of diethyleneglycol, 103 g (0.48 mol) of trimethylolpropane diallyl ether and 557 g(4.80 mol) of fumaric acid are charged and heating is started under anitrogen gas flow. The dehydration condensation reaction is conducted atan internal temperature of 190° C. using a conventional method. Afterthe acid value reached 29 KOH mg/g, 0.33 g of toluhydroquinone is added.After cooling to 150° C., an air-drying characteristics-impartingunsaturated polyester resin (UP-2), which is solid at normaltemperature, was obtained.

Reference Example 3 Preparation of Unsaturated Ester Compound (C)

[0052] In a 2 L glass flask equipped with a nitrogen gas introducingtube, a reflux condenser and a stirrer, 973 g (3.80 mol) ofpentaerythritol triallyl ether and 614 g (3.70 mol) ofmethyltetrahydrophthalic anhydride are charged and heating is startedunder a nitrogen gas flow. The esterification reaction is conducted atan internal temperature of 160° C. for 4 hours using a conventionalmethod to obtain an unsaturated ester compound (AD-1), which is liquid(viscosity: 20 dPa·s) at normal temperature.

Reference Example 4 Preparation of Unsaturated Ester Compound (C)

[0053] In a 2 L glass flask equipped with a nitrogen gas introducingtube, a reflux condenser and a stirrer, 883 g (4.13 mol) oftrimethylolpropane diallyl ether and 597 g (3.93 mol) oftetrahydrophthalic anhydride are charged and heating is started under anitrogen gas flow. The esterification reaction is conducted at aninternal temperature of 160° C. for 4 hours using a conventional methodto obtain an unsaturated ester compound (AD-2), which is liquid(viscosity: 18 dPa·s) at normal temperature.

[0054] Preparation of Resin Composition

Example 1

[0055] To a solution prepared by dissolving 60 parts of air-dryingcharacteristics-imparting unsaturated polyester resin (UP-1) obtained inReference Example 1 in 40 parts of hydroxyethyl methacrylate, 20 partsof the unsaturated ester compound (AD-1) obtained in Reference Example 3was added.

Example 2

[0056] To a solution prepared by dissolving 60 parts of air-dryingcharacteristics-imparting unsaturated polyester resin (UP-1) obtained inReference Example 1 in 40 parts of hydroxyethyl methacrylate, 20 partsof the unsaturated ester compound (AD-2) obtained in Reference Example 4was added.

Example 3

[0057] To a solution prepared by dissolving 60 parts of air-dryingcharacteristics-imparting unsaturated polyester resin (UP-2) obtained inReference Example 2 in 40 parts of hydroxyethyl methacrylate, 20 partsof the unsaturated ester compound (AD-1) obtained in Reference Example 3was added.

Example 4

[0058] To a solution prepared by dissolving 60 parts of air-dryingcharacteristics-imparting unsaturated polyester resin (UP-2) obtained inReference Example 2 in 40 parts of hydroxyethyl methacrylate, 20 partsof the unsaturated ester compound (AD-2) obtained in Reference Example 4was added.

Comparative Example 1

[0059] 60 Parts of air-drying characteristics-imparting unsaturatedpolyester resin (UP-1) obtained in Reference Example 1 was dissolved in40 parts of a styrene monomer.

Comparative Example 2

[0060] 60 Parts of air-drying characteristics-imparting unsaturatedpolyester resin (UP-1) obtained in Reference Example 1 was dissolved in40 parts of methyl methacrylate.

Comparative Example 3

[0061] 60 Parts of air-drying characteristics-imparting unsaturatedpolyester resin (UP-2) obtained in Reference Example 2 was dissolved in40 parts of hexanediol dimethacrylate.

Comparative Example 4

[0062] 60 Parts of air-drying characteristics-imparting unsaturatedpolyester resin (UP-1) obtained in Reference Example 1 was dissolved in40 parts of hydroxyethyl methacrylate.

[0063] Test Procedure and Evaluation

[0064] Evaluation of “Less Odor Characteristics”

[0065] The resulting curable unsaturated resin composition is charged inan open vessel and the odor, which is detectable to a tester at theposition that is 5 cm away from his nose, is rated as follows.

[0066] Criteria for Rating Less Odor Characteristics

[0067] ◯: no odor at the position that is 5 cm away from the nose

[0068] Δ: subtle odor at the position that is 5 cm away from the nose

[0069] X: strong odor at the position that is 5 cm away from the nose

[0070] Evaluation of “Drying Characteristics in Coating Film”

[0071] To 100 parts of the resulting curable unsaturated resincomposition, 0.5 parts of 6% cobalt naphthenate (Co-NAPHTHENATE 6%,manufactured by DAINIPPON INK & CHEMICALS Co., Ltd.) and 1.5 parts ofmethylethylketone peroxide (Permeck N, manufactured by NOF CORPORATION)are added in a glass beaker, followed by stirring. The resulting mixtureis applied on a glass sheet at 25° in each of a thickness of (i) 254 μmand (ii) 76 μm using an applicator to obtain test samples. At that time,the time required for the adhesion of the surface of the coating film(i) to disappear is referred to as a “thick film drying time”, while thetime required for the adhesion of the surface of the coating film (ii)to disappear is referred to as a “thin film drying time”. The timerequired for the curable unsaturated resin composition in the beaker tocure (based on JIS-K-6901.4.8) is referred to as the “curing time”.TABLE 1 Evaluation of less odor characteristics Examples ComparativeExamples 1 2 3 4 1 2 3 Resin UP-1 60 60 — — 60 60 — compo- UP-2 — — 6060 — — 60 sition β-HEMA 40 40 40 40 — — — SM — — — — 40 — — MMA — — — —— 40 — HDDMA — — — — — — 40 AD-1 20 — 20 — — — — AD-2 — 20 — 20 — — —Less odor characteristics ◯ ◯ ◯ ◯ X X Δ

[0072] TABLE 2 Evaluation of drying characteristics in coating filmComparative Examples Examples 1 2 3 4 2 3 4 Resin UP-1 60 60 — — 60 — 60compo- UP-2 — — 60 60 — 60 — sition β-HEMA 40 40 40 40 — — 40 MMA — — —— 40 — — HDDMA — — — — — 40 — AD-1 20 — 20 — — — — AD-2 — 20 — 20 — — —Curability (min.) 20 20 20 20 40 60 20 Thick film drying 1.5 2 2 2.5 5 61.5 characteristics (hours) Thin film drying 1.8 2.5 2.3 3.0 10< 10< 8characteristics (hours)

[0073] In the tables described above, β-HEMA is hydroxyethylmethacrylate, SM is styrene, MMA is methyl methacrylate, and HDDMA ishexanediol dimethacrylate.

[0074] Hydroxyethyl methacrylate used in the present invention has highboiling point and high flash point as compared with styrene, as shownbelow, and has high safety. TABLE 3 Boiling Flash point (° C.) point (°C.) Styrene 145 31 Hydroxyethyl 205 107 methacrylate

INDUSTRIAL APPLICABILITY

[0075] The curable unsaturated resin composition of the presentinvention can provide excellent coating materials and coatingcompositions for woodworking because it has less odor characteristicsand high safety and is also superior in thin film drying characteristicsin a coating film.

1. A curable unsaturated resin composition comprising a polymerizableunsaturated resin (A) having two or more polymerizable unsaturateddouble bonds in a molecule, a hydroxyalkyl (meth)acrylate (B), and anunsaturated compound (C) having one or more cyclohexene rings and two ormore allyl ether groups in a molecule, which is liquid at normaltemperature.
 2. The curable unsaturated resin composition according toclaim 1, wherein the hydroxyalkyl (meth)acrylate (B) has an alkyl grouphaving 1 to 4 carbon atoms.
 3. The curable unsaturated resin compositionaccording to claim 1, wherein the unsaturated compound (C) is anunsaturated ester compound having a number-average molecular weight of1000 or less derived from a carboxylic acid having a cyclohexene ringand a hydroxy compound having two or more allyl ether groups in amolecule.
 4. The curable unsaturated resin composition according toclaim 1, wherein the unsaturated compound (C) is derived from carboxylicacid having a cyclohexene ring and a hydroxy compound having two or moreallyl ether groups in a molecule, and has a viscosity of 10 to 100dPa·s.
 5. The curable unsaturated resin composition according to claim3, wherein the carboxylic acid is cyclohexenedicarboxylic acid, whichmay have an alkyl substituent, and the hydroxy compound is a polyallylether of a polyhydric alcohol.
 6. The curable unsaturated resincomposition according to claim 4, wherein the carboxylic acid iscyclohexenedicarboxylic acid, which may have an alkyl substituent, andthe hydroxy compound is a polyallyl ether of a polyhydric alcohol. 7.The curable unsaturated resin composition according to claim 1, whichcontains 25 to 85% by weight of the polymerizable unsaturated resin (A),10 to 55% by weight of the hydroxyalkyl (meth)acrylate (B), and 5 to 20%by weight of the unsaturated compound (C).
 8. The curable unsaturatedresin composition according to claim 1, wherein the polymerizableunsaturated resin (A) is one kind selected from unsaturated polyesterresin, epoxy (meth)acrylate, urethane (meth)acrylate and polyester(meth)acrylate.
 9. The curable unsaturated resin composition accordingto claim 1, wherein the polymerizable unsaturated resin (A) is anair-drying characteristics-imparting unsaturated polyester having anallyl ether group and/or a cyclohexene ring.